The scientists conducted the study with 989 volunteers for 3 years. During the experiment, they used a night light, a light source that was hung from the ceiling.
The penetration of light reduces melatonin levels.
According to experts, there is a clear link between the intensity of night light and the development of atherosclerosis, a chronic disease that leads to the formation of plaque on the walls of arteries.
According to one of the study's authors, Kenji Obayashi, the penetration of light through the closed eyelid reduces the level of melatonin, also known as the "hormone of the night".
According to him, the result is a disrupted circadian clock , which can eventually lead to various heart diseases and even strokes. Therefore, the team has warned the use of nightlights and other light sources during sleep.